Variety-specific arsenic accumulation in 44 different rice cultivars (O. sativa L.) and human health risks due to co-exposure of arsenic-contaminated rice and drinking water

Arsenic (carcinogenic) is a global health concern due to its presence in groundwater and subsequent accumulation in cultivated-rice via irrigation. The present work focused on the evaluation of arsenic concentration in groundwater, different cultivated-rice varieties (studied together for the first-time) and related health-risks. Arsenic in groundwater (0.26-0.73 mg/L) exceeded the World Health Organization limit for drinking water (0.01 mg/L). Arsenic concentration in rice-grains was found in the range: < 0.0003-2.6 mg/kg dry-weights, where 42 rice varieties (out of total 44) exceeded the Codex Alimentarius Commission limit of polished-rice (0.2 mg/kg). The variety-specific differential-response of arsenic-accumulation was observed (first-time report), where high yielding rice varieties (HYV) were more prone to accumulate arsenic in comparison to local varieties (LV), however, 'Radhunipagol' (an aromatic LV) exhibited as a moderate arsenic-accumulator (BCF = 2.8). The cumulative estimated-daily-intakes (EDICumulative) of arsenic in central-tendency-exposure were observed to be 0.029, 0.031 and 0.04 mg/kg-day among children, teenagers and adults, respectively. The EDICumulative for possible reasonable-maximum-exposure among the above mentioned subpopulation was 0.038, 0.04 and 0.05 mg/kg-day, respectively. The evaluated Cumulative Hazard Index and Individual Excess Lifetime Cancer Risk values suggested that the studied population is under extremely severe cancerous and noncancerous risks to arsenic co-exposures via drinking water and rice.

Automated summary

Arsenic, a carcinogen, is found in high levels in groundwater and cultivated rice, particularly in high-yielding varieties. The population studied in this research is exposed to extremely severe cancer and noncancer risks due to co-exposure to arsenic through drinking water and rice consumption.